Re: Initial cross-compilation support

[Andreas Enge <andreas@enge.fr>]

Am Mittwoch, 27. Februar 2013 schrieb Ludovic Courtès:
> Commit 827d289 of the ‘core-updates’ branch adds cross-base.scm, which
> builds a cross tool chain.
> 
> So if you type ‘guix build gcc-cross-mips64el-linux-gnu’, you get a
> cross-compiler (+ libc, binutils) for that platform.  The compiler is
> slightly modified by this patch:

Congratulations! I tried the build and it worked without problem.

Am Sonntag, 3. März 2013 schrieb Nikita Karetnikov:
> > I’m making progress, but it may still be a week before it’s all in
> > place.
> 
> I'm willing to try this [1].  What should I adjust to build with n64?

Currently, "file /nix/store/bxxk1jih4qy1hs7s22hp4f0i98b1ldn6-gcc-cross-
mips64el-linux-gnu-4.7.2/mips64el-linux-gnu/lib/libgcc_s.so.1" returns

ELF 32-bit LSB shared object, MIPS, N32 MIPS-III version 1 (SYSV), 
dynamically linked, with unknown capability 0xf41 = 0x756e6700, with 
unknown capability 0x70100 = 0x1040000, not stripped

I think one needs to add the configure parameters "--with-arch=mips64 --
with-abi=64" to the cross build of gcc; and maybe "-march=mip64 -mabi=64" 
to the binutils and glibc. Ludovic should know best where to do it in the 
code. And then, if one wishes to extract bootstrap binaries for arbitrary 
target architectures (which are still needed, I suppose?), I assume one 
would have to modify bootstrap.scm to use the cross gcc instead of the 
native one.

Andreas